No-name-yet
When it was first being developed in early 2004, the distribution that would later become known as "Ubuntu", was only known by its codename "no-name-yet".
An announcement list for the project was published on no-name-yet.com.
The first announcement on September 15, 2004 was from Benjamin Mako Hill, and starts:
Most of you receiving this mail registered for the low-traffic announcement list at no-name-yet.com. This is our first announcement! Before we get to the good stuff I'm pleased to announce that we are nameless no more... the name of our distribution is "Ubuntu" (read below for details) and the company supporting the project is Canonical Ltd.
And goes on to announce Warty Warthog as the first official release.
It also mentions the publication of the Ubuntu wiki:
The wiki contains most of the information and documentation on Ubuntu that the team has written thus far as they've worked up until now. You are welcome to edit and add to the wiki although you will need to log in first. You log in by clicking on UserPreferences in the top right hand corner of the page.
You can still read the full text of the announcement.